Significant advances have been achieved in the uses of olefin metathesis for organic synthesis recently (Handbook of Metathesis, Vols. I-III, Grubbs, R. H., ed.; Wiley-VCH, 2003; and Michalak, M.; Guajski, .; Grela, K. “Alkene Metathesis” in: Science of Synthesis: Houben-Weyl Methods of Molecular Transformations, Vol. 47a Alkenes, de Meijere, A., ed.; Georg Thieme Verlag KG, 2010, pp. 327-438).
The literature relevant to catalysis proposes describing the ruthenium-containing catalysts for olefin metathesis as (pre)catalysts, since it is not proven whether the compounds, that under certain circumstances would catalyse the olefin metathesis, are identical with the active substances participating in the metathesis reaction or not (see, R. R. Schrock, J. Mol. Catal. A: Chem. 213, 21 (2004)). Because of that, the inventors use the term (pre)catalyst in this specification, wishing not to be bound by any particular theory describing the metathesis reaction mechanisms.
Several ruthenium carbene complexes are known in the state of the art, that have both a high activity in various variants of the metathesis reactions as well as a broad tolerability for functional groups. The above-mentioned combination of properties is a prerequisite of catalysts of such type in the organic synthesis. Exemplary complexes of this type are the (pre)catalysts (A), (B) and (C) (A—S. P. Nolan, Organometallics, 18, 25, (1999), B—R. H. Grubbs, Org. Lett. 1, 9, (1999), C—A. H. Hoveyda J. Am. Chem. Soc. 122, 34, (2000)).

However, there are few complexes known that effectively promote formation of tetra-substituted olefins. Examples of this type of complexes include the (pre)catalysts (D), (E), and (F) (D and E—R. H. Grubbs, Org. Lett., 9, 8, (2007); F—H. Plenio, Chem. Eur. J., 16, 41, (2010)).

The major drawback of the complexes (D) and (E) is their limited stability both in the solid state and in the solution, what poses problems related to their storage and limits their effectiveness in the metathesis reactions. The complexes such as (F) are much more stable and effective in metathesis reactions, but their preparation requires using the corresponding (pre)catalyst containing pyridinium ligands (the so-called third generation catalyst) as a substrate, as well as the compounds containing silver atom in their structure, what significantly extends the synthetic pathway and drastically increases the synthesis costs.
The third-generation complexes, such as (G) and (H), are the useful (pre)catalysts for metathesis of olefins. They are characterised by rapid initiation as well as high effectiveness and selectivity in some ring-opening metathetic polymerisation reactions (ROMP).

In turn, the complexes containing an indenylidene ligand in their structure, such as, for example, the complex (G), are very stable both in the solid state and in the solution. There are no known complexes in the state of the art that would contain the indenylidene ligand and the o-tolyl ligand.
The organometallic complexes of ruthenium containing the o-tolyl ligand are described in the patent documents Nos. EP 1971616 A, U.S. Pat. No. 8,008,224 B2, JP 2009519947 A, KR 20080103961 A, and CN 101460513.
The organometallic complexes of ruthenium, being the third-generation (pre)catalysts, containing the o-tolyl ligand and a pyridine molecule, are described in the international patent application No. WO 2007/075427 A1.